1. Field of the Invention
The present invention relates to a connector for use in piping connection for fluid, for example, fuel, cooling water, etc., and more particularly to a connector with check function of enabling confirmation from the outside as to whether piping connection is established completely.
2. Description of the Related Art
Recently, a so-called quick connector has been used for piping connection of fuel supply in a vehicle or the like. According to this connector, one pipe to be connected is provided with an annular protruding portion on the outer periphery at the end portion while the other pipe to be connected is coupled to a nearly cylindrical housing (connector housing). Thus, when the end portion of the pipe is inserted into the housing, the annular protruding portion engages with an engaging member called a retainer installed inside the housing, thereby allowing the pipe to be coupled with the housing through a one-touch operation. Also, another quick connector that uses a retainer having a gate-type inserting piece has been known. According to this connector, after the end portion of the pipe is inserted into the housing, the inserting piece of the retainer is inserted so as to engage with the annular protruding portion.
The quick connectors as described above are advantageous in that a piping work can be performed readily and swiftly. However, in a state where the end portion of the pipe is inserted into the housing, it is difficult to confirm whether the annular protruding portion completely fits into the retainer through a mere sight of the connector from the outside. Hence, in the event that fluid is flown when the connection is incomplete due to a mistake in the piping work or the like, there is a possibility that the connection is disconnected and fluid starts to leak.
Accordingly, JP-A-10-141567 proposes an arrangement using a connector, in which the housing has an axially restricted portion and a pair of window portions penetrating through the housing in a radius direction and provided oppositely in a circumferential direction, and the retainer, inserted and held inside the housing, has a pair of claw portions elastically deformable in the radius direction and provided at positions corresponding to the window portions. The claw portions include inclined inner surfaces inclined inwardly in the radius direction from the opening end to the inner side in the axial direction of the housing, on which the annular protruding portion slides with pressing when the pipe is introduced inside, and a hooking portion that hooks on the annular protruding portion when coupling is made and thereby restricts fall-off of the pipe. Herein, a confirming member, which has an axially restricting portion stopped at the axially restricted portion through engagement and thereby restricting relative movement in the axial direction, and a C-shaped member expandable in diameter through elastic deformation, is provided to the outer peripheral surface of the housing of the connector to be held externally from a direction at right angles to the axis. The C-shaped member is stopped at the edges of the window portions through engagement, and when coupling is completed by fully introducing the pipe inside, the C-shaped member is expanded in diameter by the claw portions. This allows the confirming member to be removed, based on which a coupling state can be confirmed.
Patent Document 1: JP-A-10-141567
The connector provided with the confirming member enables confirmation of connection through removal of the confirming member from the housing after the pipe is introduced and coupled to the housing that is coupled to the other pipe. However, in a case where the pipe is disconnected by releasing the engagement with the connector and reconnected, there arises a problem that the coupling state can no longer be confirmed because the confirming member has been removed. In this case, the confirming member may be stored and attached again to the housing at the time of reconnection; however, such a work is so tedious that it does not meet the practical need.